Cartridge-powered impact wrench



Aug. 10, 1965 R, T. cA'rLlN ETAL 3,199,612

CARTRIDGE-POWERED IMPACT WRENCH Filed Oct. 30, 1962 2 Sheets-Sheet lSSII I M fila rAnPA-I Aug. 1U, 1965 R. T. cATLlN ETAL 3,199,512

CARTRIDGE-POWERED IMPACT WRENCH Filed Oct. 30, 1962 2 Sheets-Sheet 2United States Patent O 3,199,612 CARTRIDSE-PWEREE IMPACT WRENCH RobertT. @atlin and Robert 0. Swain, Trumbull, Conn.,

assigner-s to Remington Arms tompany, Inc., Bridgeport, Conn., acorporation of Delaware Filed Get. 3G, 1952, Ser. No. 234,116 9 tlaims.(El. 173-93) This invention relates generally to a cartridge poweredimpact tool whereby a high velocity force is provided and transmitted toa fastening means in order to loosen or tighten the fastening means.

More specifically, the invention relates to a cartridge powered impactwrench utilizing a unique and novel tire control mechanism.

It is an object of this invention to provide a light-weight, portableimpact wrench which is especially adapted to be used in the iield or inareas where there is no outside source of power such as electricity,compressed air, etc.

It is another object of this invention to provide an explosive-actuatedimpact wrench which is compact and which has a relatively small amountof recoil when tired.

Another obliect of this invention is to provide a novel low-cost tirecontrol mechanism which includes a positive trigger means which can betired after the mechanism has first been set in ready-to-iire position.

The present invention 'was conceived to satisfy a need for a portableimpact wrench which requires no hose or outside source of power. Byproviding a cartridgepowered impact wrench it is possible to eliminatecostly electrical or pneumatic equipment, as well as eliminate thenecessary cables associated with electrical and/or pneumatic tools. Notonly are the cables expensive and very easily damaged on constructionsites but they are a constant source of trouble because of safetyhazards and the provision which must be made to move men and equipmentover and around the cables.

Moreover, a cartridge-powered piston can be accelerated to a highervelocity with a shorter stroke than other types of impact wrenches. Thisoffers the following advantages over a pneumatic wrench of the samecapacity: (1) lighter weight, (2) smaller, shorter, more compact, (3)higher velocity, lower mass for a given energy output which results inless wrench recoil, (4) high velocity impact will loosen or tighten to agreater degree than a low velocity blow, portable feature mentionedabove.

An important additional advantage of providing cartridge-powered meansto an impact wrench is that the amount of torque provided to the wrenchcan be varied and controlled merely by using known cartridge powerloads. Thus, the amount of torque which a specific tool will produce forvarious cartridge power loads can be predetermined and plotted. A. user,knowing the required torque, can select the correct cartridge to givehim the desired torque, and after pre-loading the wrench manually totake up the slack of the nut or fastening member, can fire the tool andconsistently control the amount of torque which is applied to thefastening member.

Other features and advantages of the improved tool of the presentinvention will be apparent from reading the enclosed specification andclaims and shown in the drawings in which:

FIGURE 1 shows a longitudinal sectional view of the preferredembodiment.

FIGURE 2 shows a front end view of FIGURE 1.

FIGURE 3 shows a sectional view of the re control mechanism in the atrest position.

FIGURE 4 shows a view of the pin and slot arrangement taken on line 4-4of FIGURE 3.

FIGURE 5 shows a sectional view of the tire control recess 15.

3,199,612 Patented Aug. 19, 1965 mechanism in the cocked or ready totire position.

FIGURE 6 shows a view of the pin and slot means taken on line 6 6 ofFIGURE 5.

FIGURE 7 shows the fire control means after the trigger has beenreleased.

FIGURE 8 shows a cross-sectional view taken on line 8-8 of FIGURE 7.

FIGURE 9 shows a longitudinal sectional view of a modified impactwrench.

FIGURE 10 shows a view of the cam pin and slot arrangement while the pinis in the normal forwardly biased position.

In the preferred embodiment shown in FIGURE 1, a cylindrical barrel 1has one end connected to the tire control assembly 2 and the oppositeend connected to a yoke and anvil assembly 3. The yoke assembly 3includes a yoke 4 having an upper portion 5 parallel to and inlongitudinal alignment with barrel 1 and detachably attached thereto bythread means 6. Attached to upper portion 5 and projecting transverselyof barrel 1 are parallel, laterally spaced leg portions 7 and 8 (FIGURE2) having openings 9 and 10 therein. Yoke 4 is grooved to provideangular faces 11 and 12 which with the inside faces 13 and 14 of legportions 7 and 3 form a central (See FIGURE 2.)

An anvil 16 having a round portion 17 and an offset angular portion 1Sis positioned in recess 15 and is rotatably mounted on legs 7 and 8 in amanner explained below. The angular anvil portion 18 has an impactreceiving face 19 which abuts against upper yoke face 11 when in theready-to-re position. (See FIGURE 1.)

Positioned in openings 9 and 10 of the yoke leg portions 7 and .8 andadapted to rotate therein are bushing members Ztl and 21, having squareopenings 22 and 23, respectively, in alignment with a similar squareopening 24 inV anvil 16. Extending through the square openings 22, 23and 24, and projecting outwardly of the spaced leg portions 7 and 8 is asquare drive member 25. It will be seenV from the above that upon -anvil16 being rotate-d, the square drive will move with the anvil as willbushings 2@ and 21. It should be appreciated that openings 22, 23 and 24and drive member Z5 can have other angular configurations than a squareand still be effective.

Longitudinally slidable within the barrel 1 and elongated opening 26 inyoke 4 is an elongated piston assembly 27 whose function it is todeliver the necessary force to the impact receiving face 19 of anvilportion 18 in order to rotate the anvil and thereby rotate the squaredrive member 25, in which is connected the necessary wrench socket orscrew driver. Obviously, various types of fastening tools can beattached to the square drive member.

Piston assembly 27 includes an elongated rod 27a which is detachablyattached to an enlarged rear head portion 27b by any well-known meanssuch as threads 27C. Positioned intermediate the ends of the piston rodis an abutment 27d which acts as a safety means to prevent the rod frombeing projected out of the barrel at high velocity in case threads 27Cshould fail. y

Spacer member 28 is positioned within the forward portion oi barrel 1and has its front end abut yoke 4 at 29 and its rear end in abuttingengagement at 30 with an impact plate head 31. A plurality of resilientbuffer blocks 32, separatedby impact plates 33, are loosely mounted onrod 27 to permit relative sliding movement and are designed to absorbthe initial shock and to return the piston rod to its original positionas shown in FIGURE 1. The spacer 28 limits the relative forward movementof the buffer and plate members.

Threadedly attached at the rear end of the barrel is a chamber 34 havinga cavity 35 in which projecting rear head 36, which is integral withenlarged piston portion 27b, is positioned. An opening 37 is providedthrough chamber 34 in which a chamber bushing 38 is placed, said chamberbushing being adapted to'receive an explosive cartridge 39. Chamber 34also has an end portion 40 of reduced diameter to which the lire controlassembly 2 is threadedly attached as at 41.

Inasmuch as the re control assembly 2 is the same in the modilicationsshown in FIGURE 1 and FIGURE 9, only one explanation will be made. Thisassembly consists of an open-end cylindrical housing 42 having closedslot means 43 and 44 provided in the sidewalls and a guide plate 45 inwhich an offset opening 46 is provided. A breech block 47 is slidablypositioned in the open end of the housing and secured to the housing bymeans of a pin 43 secured to the breech block and slidably positioned inslot 43 of the housing.

Breech block 47 has three additional recesses or cavities in addition tothe one .in which pin 43 is secured: (l) A large recess 49 in theforward portion of the breech which is adapted to be attached to thereduced rear end portion of chamber 34 by thread means 41; (2) anelongated tapered longitudinal cavity t) ecceutrically located in thebreech to receive lower end 51 of a tiring pin 52 which has its upperend 53 slidably mounted in opening 46 and which is prevented frombecoming disengaged by a nut 54 threaded on the end thereof; and (3) anarrow recess 55 (FIGURE 8) in which a Z-shaped trigger 56 is pivotallymounted at 57 and which projects outwardly through slot 44 of housing42. A cavity 55a, which is in communication with recess 55, has a coilspring 5517 positioned therein which abuts against trigger 56 to biasthe trigger into operative position. Opening 46 in plate 45 is offsetfrom the tapered recess 50 so that when the housing 42 is pusheddownwardly and rotated, the enlarged upper portion of recess 5t) issuicient to permit the firing pin 52 to move into substantial alignmentas shown in FIGURES 5 and 7. Although cavity 50 is shown as beingeccentrically positioned with respect to the central axis of opening 37and chamber bushing 38, this is done because rimiire cartridges are tobe used in this particular modication. It can be appreciated thatcenteriire cartridges might also be used in which case the eccentricpositioning of the cavity 5t? would not be necessary.

It will be seen from FIGURE l that two sets of springbiasing means areprovided within the lire-control assembly: (l) an outer compression coilspring 58 which bears on plate 45 and breech 47 and normally biases thebreech block 47 and housing 42 apart; and (2) a smaller, innercompression coil spring 59 encircling the elongated tiring pin 52 andbearing on plate 45 and an abutment 60 on the tiring pin so as tonormally bias the tiring pin towards the chamber and the explosivecartridge.

It can be seen from FIGURES 3 and 4 that slots 43 and 44 compriselongitudinally extending slots 43a and 44a and transverse slots 43h and44b respectively in which pin 48 and trigger 56 are adapted to slideupon relative sliding and rotational movement of the breech block 47 andhousing 42.

Operation Referring to FIGURES 3 and 4, the re control is in the at-restposition with the breech and breech pin 48 biased forwardly by spring 5Suntil the pin is stopped by the forward end of slot portion 43a. Thetiring pin 52, supported in olset openings 46 and 50, is out ofalignment with respect to the center line of cavity 50. (See FIGURE 3which has been exaggeratedv for clarity.) Trigger 56 abuts against thefront face of abutment 60 and prevents the tiring pin 52 from movingforwardly. Spring 59 is in a relatively uncompressed state and thebreech block is under the main influence of the larger spring 58. It canbe seen that the extent of travel of the firing pin can be adjusted bylimit nut 54. However, in the position of FIGURE 3, releasing thetrigger will NOT cause the device to re, since the tiring pin will belimited in its forward travel by nut 54.

Referring to FIGURE 5, the lire control has been cocked by depressingthe housing 42 and rotating it into the locked or ready to lireposition. Rotating it into the locked position has aligned the firingpin with respect to the center line of breech cavity 50, the pin 48 hasmoved into the transverse slot 43b, the springs 58 and 59 have beencompressed, and the limit nut 54 is now longitudinally spaced from plate45, thus permitting the firing pin to move the necessary distance withthe necessary velocity in order to detonate the explosive cartridge inthe chamber when the trigger is released.

FIGURE 7 shows the re control after the trigger has been squeezed andthe tiring pin has dropped. The housing is then rotated into theunlocked position, at which time the fire control returns to theoriginal position shown in FIGURE 3.

Upon ring of the cartridge, the explosive pressure generated therebymoves piston rod 27 forwardly at high speed to strike against the face19 of the anvil 16 which rotates along with the square drive 25.Depending on what is attached to the square drive member and how it isattached, a sharp torque force is provided which can instantly tightenor loosen a fastening. Thus, a socket wrench or a screw driver (notshown) can be provided on the square drive 25 which can tighten orloosen a bolt or screw quickly. Left or right hand rotation is obtainedby inverting the wrench and selecting either end of the square drive.The anvil and square drive are preloaded by rotating the handle.

It can be seen that the oifset anvil design described above isespecially applicable in areas in which the distance from the worksurface to an adjacent structure is less than the overall length of thetool. The tool shown in FIGURE l can be used in close quarters botheffectively and eficiently.

A modified cartridge-powered impact wrench is shown in FIGURES 9 and 10.As mentioned above, the re control mechanism is similar to thatdescribed above and need not be described again. Referring to FIGURE 9,it can be seen that a cylindrical barrel 61 is provided having a chamberassembly 62 attached thereto at one end as explained above. A pistonassembly 63 is slidably positioned within the barrel and extends throughopenings in buffer blocks 64, impact plate 65, and head impact plate 65.Head impact plate 66 abuts spacer member 67, whose forward movement islimited by a muzzle cap 68 which is attached to the front end of thebarrel by thread means 69.

An open-end cylindrical housing 76 is then positioned within spacer 67and held thereon by a pin and slot arrangement consisting of retainingpin 71 which is inserted through aligned, horizontally-extending slots72 and in the sidewalls of the spacer and barrel, respectively, andthrough a transverse elongated opening 74 in the housing 70. Thisstructure permits a limited amount of relative longitudinal movementbetween the housing and the spacer and barrel and prevents rotationalmovement between the parts.

Positioned within the housing 70 and projecting.

through the open end thereof and through an opening 75 in the muzzle capis an impact driver 76. The outer end 77 of the impact driver is adaptedto be connected to a socket wrench or any other fastening part or toolwhich is desired to be turned. The inner end of the driver 76 telescopeswithin the housing and is connected thereto by a transverse cam pin '78which extends through opening 79 in the driver and into opposed V-shapedslots 80 and 81 located in opposite sidewalls of the housing. GroovesSBR, 801.. and 81K, 81L (not on drawing) are positioned on oppositesides of the apex of each V- shaped slot for a purpose explained below.Coil spring 2 is placed within cavity 83 ofthe housing and biases thedriver 76 forwardly so that the cam pin 78 will ride in the V-shapedslots 80 and 81 in whichever leg of the V that the pin happens to bepositioned. FIGURE shows the pin 78 placed in groove 80L for left handmovement of the driver 76.

Operation of modz'jczztion Upon squeezing of the trigger, the cartridgeis red as explained above and the explosive pressure moves pistion 63forwardly at high speed to impact against the rear end of housing 70.The impact is absorbed by buffers 64 Whose forward movement isrstoppedwhen head impact plate 66 abuts the rear end of spacer 67. Housing 70 isthrust forwardly by the impact of the piston rod and is stopped when theretaining pin 71 reaches the forward ends of slots 72 and 73 in thespacer and the barrel. Prior to releasing the trigger and depending onwhether a right or left-hand turn is desired, the driver 76 is rotatedto position cam pin 73 in the appropriate inclined slot and groove.Thus, as can be seen in FIGURE l0, the pin 78 is biased forwardly andpositioned in groove SGL so that upon forward longitudinal movement ofthe housing 70, the pin 78 will be cammed in the left 80A of theV-shaped slot 80 and the driver 76 will be forced to turn in acounter-clockwise or lefthand direction. If a clockwise (rightdirection) direction is desired, the pin 78 is positioned in groove SGRprior to actuating the re control assembly. The buffer means will thenreturn the piston to its required position.

What is claimed is:

1. An impact-turning tool having means at one end thereof adapted to bedetachably connected to a member toAbe turned, means in operableengagement with said detachable means to translate alongitudinally-acting force into a rotational force, a cartridge-poweredfiring mechanism adapted to provide an explosive, longitudinally-actingforce to said translating means, said liring mechanism comprising achamber means in which an explosive cartridge is positioned, a breechblock detachably connected to said chamber means, said breech blockhaving an eccentrically positioned opening therethrough, sleeve meansmounted on said breech block having an opening therein which in thenon-tiring position is laterally oiset from said breech block opening, aring pin having its lower and upper ends slidably positioned in thebreech block opening and the sleeve opening respectively, meanspermitting relative movement of said sleeve and breech block` whereinsaid tiring pin can be moved into and held in iring position whereby thelongitudinal axis of said iiring pin is in substantial alignment withthe longitudinal axis of said breech block opening, and means operableto release said tiring pin in order to strike said explosive cartridgeand release explosive pressure thus providing the longitudinal forcerequired to actuate said translating means.

2. An impact-turning tool as recited in claim 1 wherein means areprovided between said sleeve and firing pin to bias said tiring pintoward said explosive cartridge, said means operable to release saidtiring pin including lever means which normally abut said firing pin butwhich can be manually pivoted out of the way to permit said tiring pinto move forward and strike said cartridge.

3. An impact-turning tool as recited in claim 2 in which said levermeans is pivoted to the breech block.

4. An impact-turning tool as recited in claim 1 wherein said meanspermitting relative movement of said sleeve and breech block comprisespin and slot means including a longitudinally extending slot and aconnecting transverse slot which permit a limited amount of relativelongitudinal and rotational movement.

5. A re control mechanism for a powder-actuated tool comprising chambermeans having an opening therein adapted to receive an explosivecartridge, breech means Y 6 detachably connected to said chamber meansand supporting said cartridge therebetween, a longitudinally extendingopening in said breech means, sleeve means mounted on said breech means,said sleeve means having a transverse member longitudinally spaced fromsaid breech means, said member having an opening therein laterallyoffset from said opening in said breech means, alongitudinally-extending firing pin having its lower end portionslidably mounted in said breech opening and its upper end portionslidably mounted in said transverse member opening, means to bias saidring pin towards ysaid cartridge, co-acting means on said breech meansand said sleeve means to permit limited relative longitudinal androtational movement of said breech means and said sleeve means whereby,upon said sleeve means being moved axially and rotated, the longitudinalaxis of said iiring pin moves into substantial alignment with thelongitudinal axis of said breech opening, and means normally holdingsaid tiring pin in non-tiring position but manually operable to releasesaid pin to strike and detonate said explosive cartridge.v

6. A re control mechanism as recited in claim 5 in which said coactingmeans comprises slot means on said sleeve means, and a pin extendingoutwardly from said breech means slidable in said slot means.-

7. A tire control mechanism as recited in claim 5 wherein said tiringpin hold-release means comprises an angular lever means pivoted on saidbreech means and normally abutting said firing pin against the force ofsaid firing pin biasing means.

8. A iire control mechanism for an explosive-actuated tool comprisingsleeve means having an open end therein, breech means mounted in saidopen end, a cavity in the outer end of said breech means, chamber meansdetachably mounted in said breech cavity, a longitudinally-extendingbore in said chamber means in which an explosive cartridge is placed, anopening in the inner end portion of said breech means communicating withsaid cavity and said explosive cartridge, the longitudinal axis of saidbreech opening parallel to but laterally spaced from the longitudinalaxis of said chamber bore, tiring pin means having its upper end portionpivotally connected to said sleeve means and its lower end portionslidably positioned in said breech opening s0 that in the normal safeposition the longitudinal axis of said ring pin is at an angle to thelongitudinal axis of said breech opening, means to bias said breechmeans and said sleeve means apart, means to bias said firing pin downinto said breech opening, coacting means between said breech means andsaid sleeve means to permit a limited amount of relative movementthereof in an axial and transverse rotary directions to av ready-to-iireposition, and trigger means engaging said firing pin to limit movementthrough said breech opening by said firing pin biasing means, saidtrigger means operable to be pivoted outwardly in order to release thetiring pin, thus tiring the device.

9. AV lire control mechanism as recited in claim 8 wherein said coactingmeans comprises an inverted L- shaped slot means in said sleeve meansand a pin meansV mounted on said breech means slidable in said slotmeans.

References Cited by the Examiner UNITED STATES PATENTS Packard et al.42-70.6

(Other references on foiiowing page) *2f FOREIGN PATENTS 692,741 5/40Germany.

6/54 Conrad. 8/54 Matthews.

FRED E. ENGLETHALER, Primary Examiner.

8 Smyres. Belsky. Hoffman. Hoffman.

JULIUS E. WEST, Examiner.

1. AN IMPACT-TURNING TOOL HAVING MEANS AT ONE END THEREOF ADAPTED TO BEDETACHABLY CONNECTED TO A MEMBER TO BE TURNED, MEANS IN OPERABLEENGAGEMENT WITH SAID DETACHABLE MEANS TO TRANSLATE ALONGITUDINALLY-ACTING FORCE INTO A ROTATIONAL FORCE, A CARTRIDGE-POWEREDFIRING MECHANISM ADAPTED TO PROVIDE AN EXPLOSIVE, LONGITUDINALLY-ACTINGFORCE TO SAID TRANSLATING MEANS, SAID FIRING MECHANISM COMPRISING ACHAMBER MEANS IN WHICH AN EXPLOSIVE CARTRIDGE IS POSITIONED, A BREECHBLOCK DETACHABLY CONNECTED TO SAID CHAMBER MEANS, SAID BREECH BLOCKHAVING AN ECCENTRICALLY POSITIONED OPENING THERETHROUGH, SLEEVE MEANSMOUNTED ON SAID BREECH BLOCK HAVING AN OPENING THEREIN WHICH IN THENON-FIRING POSITION IS LATERALLY OFFSET FROM SAID BREECH BLOCK OPENING,A FIRING PIN HAVING ITS LOWER AND UPPER ENDS SLIDABLY POSITIONED IN THEBREECH BLOCK OPENING AND THE SLEEVE